Air purifier

ABSTRACT

The present application provides an air purifier, which includes: a casing, a fan, a filter, and a formaldehyde removal module; the filter is in a cylindrical shape, and the formaldehyde removal module includes an inner filter, the formaldehyde removal plate is in a honeycomb shape, the inner filter screen cylinder is placed in the filter. The air purifier of the present application provides the formaldehyde removal plate at the bottom of the inner filter screen cylinder to achieve the effect of removing formaldehyde in the air. The formaldehyde removal plate is arranged in a honeycomb shape to reduce the wind resistance of the inner filter and the air resistance, thereby reducing the speed and noise of the fan.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority of Chinese Application serial No. 202111038159.9, filed on Sep. 6, 2021, the content of which is incorporated herein by reference thereto.

TECHNICAL FIELD

The present application relates to the technical field of air purification, and more particularly to an air purifier.

BACKGROUND

As people pay more attention to the environment, the use of air purifiers is increasing. Air purifiers generally draw air through a fan to generate suction, so that the air is filtered and purified by a filter assembly, and then the air is sent out from the air outlet. For vertical air purifiers, filter cylinders are generally used to suck air around the filter cylinders to improve purification efficiency. In order to improve the purification effect, especially to remove formaldehyde in the air, a filter layer is generally laminated with a formaldehyde removal layer such as an activated carbon filter element, and then folded to form a formaldehyde removal filter cylinder. However, this structure has a large wind resistance, which requires the fan to generate greater suction during purification, and the noise of the fan increases, which results in a louder noise from the air purifier.

SUMMARY

An object of the present application is to provide an air purifier, in order to solve the problem that the existing air purifiers use formaldehyde removal filter cylinder, which results in large wind resistance and generates louder noise during purification.

In order to solve above object, the technical solution used in the present application is to provide an air purifier, which includes:

a casing;

a fan, mounted in the casing; and

a filter, mounted in the casing, the casing is provided with air inlet holes at a position adjacent to the filter, and at an end of the casing adjacent to an air outlet end of the fan is provided with an air outlet;

the filter is in a cylindrical shape, the air purifier further includes a formaldehyde removal module, and the formaldehyde removal module includes an inner filter, the inner filter includes an inner filter screen cylinder arranged in a cylindrical shape and a formaldehyde removal plate configured for removing formaldehyde in air, the formaldehyde removal plate is mounted at a bottom of the inner filter screen cylinder, and the formaldehyde removal plate is in a honeycomb shape, the inner filter screen cylinder is placed in the filter, and an upper end of the inner filter screen cylinder is fitted and connected with an upper end of the filter.

In an optionally embodiment, the total area of openings on the formaldehyde removal plate is set as S, an outer diameter of the formaldehyde removal plate is set as W, and a side length of the openings is set as a, and:

$S = {\frac{3}{2}\sqrt{3}a^{2} \times {\left\lbrack {1 + {6 \times \left( {\frac{W}{\sqrt{3}a} - 1} \right)}} \right\rbrack.}}$

In an optionally embodiment, a distance between an outer surface of the inner filter screen cylinder and an inner surface of the filter is set as d, and 6 mm≤d≤9 mm.

In an optionally embodiment, a height of the filter is set as H1, and a distance from the formaldehyde removal plate to a bottom of the filter is set as H2, and H2≥⅓H1.

In an optionally embodiment, an area of the formaldehyde removal plate is set as M, and an inner diameter of an air inlet of the fan is set as D, and:

${1.3 \times {\pi\left( \frac{D}{2} \right)}^{2}} \leq M \leq {1.4 \times {{\pi\left( \frac{D}{2} \right)}^{2}.}}$

In an optionally embodiment, the fan includes a housing, a wind wheel mounted in the housing, and a motor configured for driving the wind wheel to rotate, the housing is mounted in the casing, an inner diameter of an air outlet end of the housing is set as D1, and an outer diameter of the wind wheel is set as D2, and 1.2≤D1/D2≤1.6.

In an optionally embodiment, the wind wheel includes a plurality of moving blades, an air inlet guiding ring and a baffle, the baffle is connected to the motor, and the moving blades are connected to the air inlet guiding ring and the baffle; the air inlet guiding ring is bent from an outer circumference of the wind wheel to a direction of a central axis of the wind wheel in a direction away from the baffle; an air inlet end of the housing is extended inwardly to provide with a support plate, the support plate is provided with the air inlet, and an end of the air inlet guiding ring away from the baffle is supported on the support plate.

In an optionally embodiment, an inner diameter of the air inlet is set as D, and D2-15 mm≤D≤D2-20 mm.

In an optionally embodiment, the inner filter screen cylinder is a photocatalytic filter screen, and the formaldehyde removal module further includes a light source configured for illuminating the inner filter screen cylinder, and the light source is mounted in the casing.

In an optionally embodiment, the light source is an LED module placed above the inner filter screen cylinder.

The beneficial effects of the air purifier provided by the embodiments of the present application are: compared with the prior art, the air purifier of the present application provides the formaldehyde removal plate at the bottom of the inner filter screen cylinder to achieve the effect of removing formaldehyde in the air. The formaldehyde removal plate is arranged in a honeycomb shape to reduce the wind resistance of the inner filter and the air resistance, thereby reducing the speed and noise of the fan. The cylindrical-shaped filter with the inner filter screen cylinder placed in the filter can reduce the occupied space, and the air filtered by the filter can better enter the inner filter and then enter the fan, which has a higher purification efficiency. The upper end of the inner filter screen cylinder being fitted and connected with the upper end of the filter can allow more air to pass through the formaldehyde removal plate to enhance the ability to remove formaldehyde.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to explain the embodiments of the present application more clearly, a brief introduction regarding the accompanying drawings that need to be used for describing the embodiments of the present application or the prior art is given below; it is obvious that the accompanying drawings described as follows are only some embodiments of the present application, for those skilled in the art, other drawings can also be obtained according to the current drawings on the premise of paying no creative labor.

FIG. 1 is a structural schematic front view of an air purifier provided by an embodiment of the present application;

FIG. 2 is a first structural schematic sectional view taken along a line A-A in FIG. 1 ;

FIG. 3 is a second structural schematic sectional view taken along a line A-A in FIG. 1 ;

FIG. 4 is a schematic view of an explosive structure of the air purifier shown in FIG. 1 ;

FIG. 5 is a structural schematic view in FIG. 3 when the filter and the inner filter screen cylinder are separated;

FIG. 6 is a structural schematic view of an air purifier shown in FIG. 1 when the filter is separated;

FIG. 7 is an enlarged view of a portion of FIG. 6 ;

FIG. 8 is an enlarged view of a portion of FIG. 6 ;

FIG. 9 is a structural schematic view of an upper housing of the air purifier shown in FIG. 3 ;

FIG. 10 is a schematic structural view of a fan in the air purifier shown in FIG. 3 ;

FIG. 11 is a schematic sectional view of the fan in the air purifier shown in FIG. 10 ;

FIG. 12 is a schematic view of an explosive structure of the fan in the air purifier shown in FIG. 10 ;

FIG. 13 is a structural schematic view of a diffuser part of the fan shown in FIG. 10 .

In the drawings, the main reference signs are listed:

-   -   100—air purifier;     -   10—casing; 11—upper housing; 110—air outlet; 111—rib;         112—connecting ring; 12—lower housing; 121—air inlet hole;         122—reinforcement ring; 123—support rib; 1231—positioning         groove; 124—notch;     -   20—fan; 21—housing; 210—air inlet; 211—support plate;         212—retracting pipe section; 2121—first constriction portion;         2122—second constriction portion; 213—convex ring;     -   214—air guiding grid; 215—support strip; 216—fixing plate;         22—wind wheel; 221—moving blade; 222—baffle; 2221—flat area;         2222—inclined area; 223—air inlet guiding ring; 2231—convex         edge; 23—motor 231—outputting shaft; 24—diffuser; 241—inner ring         plate; 242—outer ring plate; 243—stationary blade; 25—mounting         plate; 251—flat portion; 252—inclined portion; 253—through hole;         26—cover plate; 201—receiving cavity;     -   30—filter; 31—filter cylinder; 32—bottom cover; 321—convex rib;         322—positioning protrusion; 323—limiting block protrusion;         324—recess; 325—knob; 33—ring cover; 331—inner turning snap     -   40—formaldehyde removal module; 41—LED module; 42—inner filter;         421—inner filter screen cylinder; 422—formaldehyde removal         plate; 4221—hole; 423—outer turning snap;     -   51—panel; 52—support shell; 53—wind guiding shell; 531—circular         section; 532—contraction section; 533—supporting plate;     -   61—negative-ion generator; and 62—negative-ion emission needle.

DETAILED DESCRIPTION

In order to make the objects, technical solutions, and advantages of the present application clearer, the following further describes the present application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, and are not used to limit the present application.

It should be noted that when an element is referred to as being “fixed to” or “disposed on” another element, it can be directly on the other element or indirectly on the other element. When an element is referred to be “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

In addition, terms “the first” and “the second” are only used in describe purposes, and should not be considered as indicating or implying any relative importance, or impliedly indicating the number of indicated technical features. As such, technical feature(s) restricted by “the first” or “the second” can explicitly or impliedly comprise one or more such technical feature(s). In the description of the present application, “a plurality of” means two or more, unless there is additional explicit and specific limitation.

It should be understood that the directions or positional relationships indicated by the terms “center”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “inner”, “outer”, etc. are based on the drawings. The orientation or positional relationship of is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present application.

In the present application, unless there is additional explicit stipulation and limitation, terms such as “mount”, “connect with each other”, “connect”, “fix”, and so on should be generalizedly interpreted, for example, “connect” can be interpreted as being fixedly connected, detachably connected, or connected integrally; “connect” can also be interpreted as being mechanically connected or electrically connected; “connect” can be further interpreted as being directly connected or indirectly connected through intermediary, or being internal communication between two components or an interaction relationship between the two components. For the one of ordinary skill in the art, the specific meanings of the aforementioned terms in the present application can be interpreted according to specific conditions.

Regarding to “one embodiment”, “some embodiments” or “embodiments” described in the specification of the present application means that one or more embodiments of the present application include a specific feature, structure, or characteristic described in conjunction with the embodiments. Therefore, the phrases “in one embodiment”, “in some embodiments”, “in some other embodiments”, “in some further embodiments”, etc. appearing in different places in the specification are not necessarily all refer to the same embodiment, but mean “one or more but not all embodiments” unless otherwise specifically emphasized in other ways. In addition, in one or more embodiments, specific features, structures, or characteristics may be combined in any suitable manner.

The Chinese and English original texts corresponding to the English abbreviations used in the present application are as follows:

LED, referring to Light Emitting Diode.

TVOC, referring to Total Volatile Organic Compounds.

Please refer to FIGS. 1 to 3 , the air purifier 100 provided in the present application will now be described. The air purifier 100 includes a casing 10, a fan 20, a filter 30 and a formaldehyde removal module 40. The fan 20, the filter 30 and the formaldehyde removal module 40 are respectively mounted in the casing 10, and the casing 10 supports and protects the fan 20 and the filter 30 and formaldehyde removal module 40.

When the fan 20 is running, in a direction of airflow, the end where air enters the fan 20 is the air inlet end of the fan 20, and the end where the air flows out of the fan 20 is the air outlet end of the fan 20.

The casing 10 is provided with air inlet holes 121, and the air inlet holes 121 are located at positions corresponding to the filter 30. The casing 10 is further provided with an air outlet 110, and the air outlet 110 is located at one end of the casing 10 adjacent to the air outlet of the fan 20.

The formaldehyde removal module 40 is located between the filter 30 and the fan 20. The formaldehyde removal module 40 can decompose organic molecules in the passing air to decompose harmful molecules. For example, it can remove formaldehyde in the air, and can play a sterilization effect to improve purification performance.

When in use, the fan 20 runs, the air enters the casing 10 from the air inlet holes 121, and then filtered by the filter 30, and then purified by the formaldehyde removal module 40, and then enters the fan 20 through the air inlet end of the fan 20 for pressurization, and then flows out through the air outlet end of the fan 20, and then flows out of casing 10 through the air outlet 110 to achieve air purification.

Please refer to FIG. 2 , FIG. 3 and FIG. 4 , the filter 30 is arranged in a cylindrical shape. The formaldehyde removal module 40 includes an inner filter 42, which includes an inner filter screen cylinder 421 and a formaldehyde removal plate 422. The inner filter screen cylinder 421 is arranged in a cylindrical shape, and the formaldehyde removal plate 422 is mounted at the bottom of the inner filter screen cylinder 421, the formaldehyde removal plate 422 can remove formaldehyde in the air. The formaldehyde removal plate 422 has a honeycomb shape, that is, a number of honeycomb holes 4221 are formed on the formaldehyde removal plate 422. Use the honeycomb formaldehyde removal plate 422, which has smaller airflow resistance, and more airflow can pass through the formaldehyde removal plate to improve the ability of formaldehyde removal. The inner filter screen cylinder 421 can also filter the air and improve the air purification capacity. The inner filter screen cylinder 421 is placed in the filter 30 to reduce the occupied space and improve the space utilization.

The upper end of the inner filter screen cylinder 421 fits with the upper end of the filter 30, so that the outer side surface of the inner filter screen cylinder 421 is connected to the inner side surface of the filter 30, so that the gap between the inner filter screen cylinder 421 and the filter 30 can be made smaller, the inner diameter of the inner filter screen cylinder 421 can be made larger, and the area of the inner filter screen cylinder 421 can be enlarged to improve the purification capacity, and more air can pass through the formaldehyde removal plate 422 to improve the ability to remove formaldehyde.

Compared with the prior art, the air purifier 100 provided by the present application is provided with a formaldehyde removal plate 422 at the bottom of the inner filter screen cylinder 421 to achieve the effect of removing formaldehyde in the air. The formaldehyde removal plate 422 is arranged in a honeycomb shape to reduce the wind resistance of the inner filter 42 and the air resistance, thereby reducing the speed and noise of the fan 20; the cylindrical-shaped filter 30 with the inner filter screen cylinder 421 placed in the filter 30 can reduce the occupied space, and the air filtered by the filter 30 can better enter the inner filter 42 and then enter the fan 20, which has a higher purification efficiency. The upper end of the inner filter screen cylinder 421 being fitted and connected with the upper end of the filter 30 can allow more air to pass through the formaldehyde removal plate 422 to enhance the ability to remove formaldehyde.

In one embodiment, the formaldehyde removal plate 422 may be made of honeycomb activated carbon to form a honeycomb or mesh structure so as to remove harmful gases such as formaldehyde, benzene, TVOC, etc. in the air.

In one embodiment, the formaldehyde removal plate 422 may be made of a honeycomb carbon-filled filter screen, that is, a honeycomb support plate is placed between two layers of filter screens, and activated carbon particles are placed in the holes of the honeycomb support plate to form a honeycomb structure, so that harmful gases such as formaldehyde, benzene, TVOC, etc. can be removed from the air.

In one embodiment, the formaldehyde removal plate 422 may be made of a honeycomb substrate sprayed on the surface with a coating that removes harmful gases in the air. The coating can be a manganese compound layer, a photocatalytic layer or a cold catalyst layer, etc., so that the formaldehyde removal plate 422 can remove harmful gases such as formaldehyde, benzene, TVOC, etc. in the air.

In one embodiment, the inner filter screen cylinder 421 is a photocatalytic filter screen, that is to say, the inner filter screen cylinder 421 is made of a photocatalytic screen, or the inner filter screen cylinder 421 is provided with a photocatalytic screen. The formaldehyde removal module 40 also includes a light source, and the light source is mounted in the casing 10 to support the light source through the casing 10. The light source is used to illuminate the inner filter screen cylinder 421, so that the inner filter screen cylinder 421 can decompose organic molecules in the passing air to decompose harmful molecules, such as formaldehyde, benzene, TVOC, and sterilization, so as to purify and sterilize, and improve purification capacity. It is noted that, the inner filter screen cylinder 421 can also adopt a high-efficiency filter layer to improve the air purification capability.

In one embodiment, the distance between the outer side surface of the inner filter screen cylinder 421 and the inner side surface of the filter 30 is set as d, and 6 mm≤d≤9 mm. In this way, the gap between the inner filter screen cylinder 421 and the filter 30 can be made smaller, and the inner diameter of the inner filter screen cylinder 421 can be made larger, and the inner filter screen cylinder 421 can be conveniently mounted in the filter 30, and it is also convenient for the inner filter screen cylinder 421 to be removed from the filter 30. In an optional solution, d=7.7 mm, which means that the distance between the outer side of the inner filter screen cylinder 421 and the inner side of the filter 30 is set as 7.7 mm to ensure that the gap between the inner filter screen cylinder 421 and the filter 30 is small, and convenient to disassemble and assemble the inner filter screen cylinder 421.

In one embodiment, the height of the filter 30 is set as H1, and the distance from the formaldehyde removal plate 422 to the bottom of the filter 30 is set as H2, and H2≥⅓H1. This structure can reduce wind resistance and allow more air to pass through the formaldehyde removal plate 422 to improve the ability to remove formaldehyde.

In one embodiment, the total area of the hole 4221 on the formaldehyde removal plate 422 is set as S, the outer diameter of the formaldehyde removal plate 422 is set as W, and the side length of the hole 4221 is set as a, and:

$S = {\frac{3}{2}\sqrt{3}a^{2} \times {\left\lbrack {1 + {6 \times \left( {\frac{W}{\sqrt{3}a} - 1} \right)}} \right\rbrack.}}$

This structure can ensure that the wind resistance of the formaldehyde removal plate 422 is small, and the formaldehyde removal plate 422 has a larger area to remove formaldehyde and improve the formaldehyde removal capacity and air purification filtering capacity of the air purifier 100.

In an embodiment, the area of the formaldehyde removal plate 422 is set as M, and the inner diameter of the air inlet 210 of the fan 20 is set as D, and:

${1.3 \times {\pi\left( \frac{D}{2} \right)}^{2}} \leq M \leq {1.4 \times {{\pi\left( \frac{D}{2} \right)}^{2}.}}$

This structure can ensure the ability of the air purifier 100 to purify and filter the air, and ensure that the formaldehyde removal plate 422 has a larger area to remove formaldehyde and improve the formaldehyde removal ability of the air purifier 100.

In one embodiment, referring to FIGS. 2, 3 and 6 , the bottom of the casing 10 is open, the filter 30 includes a filter cylinder 31 and a bottom cover 32, and the bottom cover 32 is mounted at the bottom of the filter cylinder 31 to form a cylindrical filter 30. The inner filter screen cylinder 421 is placed in the filter cylinder 31. When assembling, the filter cylinder 31 extends into the casing 10, the bottom cover 32 is detachably covered at the bottom of the casing 10, and a plurality of air inlet holes 121 are formed on the side of the casing 10 corresponding to the position of the filter cylinder 31. Arranging the bottom of the casing 10 to be open, and the bottom cover 32 of the filter 30 is covered on the bottom of the casing 10, so as to use the bottom cover 32 of the filter 30 as the bottom cover 32 of the casing 10. When the filter 30 needs to be replaced, the bottom cover 32 is replaced with the bottom cover 32, it means that the bottom cover 32 and the filter cylinder 31 form an integrated structure as a consumable, so there is no need to worry about the wear and aging of the bottom cover 32, and the service life of the air purifier 100 can be greatly improved.

In one embodiment, the bottom cover 32 and the filter cylinder 31 are fixed into an integral structure, so that when the filter 30 is replaced, it is more convenient to disassemble and assemble.

In one embodiment, referring to FIGS. 1 to 3 , when the casing 10 includes an upper housing 11 and an lower housing 12, the air inlet holes 121 are provided on the side of the lower housing 12, and the bottom of the lower housing 12 is open, and the air outlet 110 is located on the upper housing 11.

In one embodiment, referring to FIGS. 6, 7 and 8 , the inner surface of the lower end of the casing 10 is provided with a reinforcement ring 122 to increase the structural strength of the lower end of the casing 10 so as to facilitate the mounting of the bottom cover 32 of the filter 30.

In one embodiment, the inner surface of the lower end of the casing 10 is provided with a plurality of support ribs 123. The side of the bottom cover 32 is provided with a number of convex ribs 321. The convex ribs 321 are used for supporting on the support ribs 123. That is, the bottom cover 32 can be mounted in the casing 10 through the cooperation of the convex ribs 321 and the support ribs 123. There is a notch 124 between two adjacent support ribs 123 for the convex rib 321 to pass through. That is to say, during assembly, the convex rib 321 can be inserted into the casing 10 from the notch 124 between the two adjacent support ribs 123, Then turn the bottom cover 32 to make the convex rib 321 support on the corresponding support rib 123 to mount the bottom cover 32, which is convenient for assembly. Of course, the bottom cover 32 can also be mounted on the bottom of the casing 10 through threaded fitting. It is noted that the bottom cover 32 can also be fixed on the bottom of the casing 10 with screws.

In one embodiment, when the lower end of the casing 10 is provided with a reinforcement ring 122, the support rib 123 can be provided on the reinforcement ring 122 to more stably fix the support rib 123 and ensure that the support rib 123 can stably support the convex rib 321, and then fix the bottom cover 32.

In one embodiment, a positioning groove 1231 is provided on each support rib 123, and a positioning protrusion 322 is provided on each convex rib 321. When the convex rib 321 extends into the casing 10, the bottom cover 32 is rotated such that the positioning protrusion 322 on the convex rib 321 is extended into the positioning groove 1231 on the support rib 123, the convex rib 321 and the support rib 123 are positioned to fix the bottom cover 32, which is convenient for assembly.

In one embodiment, a limiting block protrusion 323 is provided on the convex rib 321, and the limiting block protrusion 323 is used to stop the side of the support rib 123. When assembling, when the convex rib 321 extends into the casing 10, and rotates the bottom cover 32, and the side of the support rib 123 blocks the limiting block protrusion 323, that is, the limiting block protrusion 323 rotates with the bottom cover 32, when the limiting block protrusion 323 touches the side of the support rib 123, the bottom cover 32 cannot continue to rotate to limit the rotation of the bottom cover 32, and then the rotation position of the convex rib 321 can be determined to ensure that the convex rib 321 is well supported on the support rib 123 to secure the bottom cover 32 mounted on casing 10. In addition, when the bottom cover 32 is removed, the structure can rotate the bottom cover 32 in a reverse direction. When the limiting block protrusion 323 touches the side of the adjacent support rib 123, the bottom cover 32 can be taken out, and then the filter 30 can be taken out to facilitate the replacement of the filter 30.

In one embodiment, the bottom surface of the bottom cover 32 is provided with two recesses 324 spaced apart, and a knob 325 is formed between the two recesses 324 to facilitate the rotation of the bottom cover 32 and to facilitate the mounting of the bottom cover 32 on the bottom of the casing 10. In addition, this structure can also keep the bottom surface of the knob 325 and the bottom surface of the bottom cover 32 level, so as to be placed on the surface of the medium, thereby facilitating the placement of the air purifier 100.

In one embodiment, the filter 30 further includes a ring cover 33, and the ring cover 33 is mounted on the upper end of the filter cylinder 31 to increase the structural strength of the filter 30 and better ensure the filter cylinder 31.

In one embodiment, referring to FIG. 2 , FIG. 3 , and FIG. 8 , the light source may be an LED module 41 for more energy saving.

In one embodiment, referring to FIG. 5 , an inner turning snap 331 can be arranged on the ring cover 33, and an outer turning snap 423 can be arranged on the inner filter screen cylinder 421, and the inner turning snap 331 is engaged to the outer turning snap 423 to fix the inner filter screen cylinder 4211 and the ring cover 33. It is noted that the upper end of the inner filter screen cylinder 421 can also be directly supported on the casing 10.

In some embodiments, an internal thread can be provided on the upper end of the filter cylinder 31, and an external thread can be provided on the upper end of the inner filter screen cylinder 421, so that the inner filter screen cylinder 421 and the filter cylinder 31 can be fixedly connected with each other through the fitting of the internal thread and the external thread. This structure can make the air filtered by the filter cylinder 31 need to be processed by the inner filter screen cylinder 421, which can improve the ability and efficiency of air purification.

In one embodiment, an internal thread may be provided on the ring cover 33, and an external thread may be provided on the inner filter screen cylinder 421, so that the inner filter screen cylinder 4211 and the ring cover 33 are fixedly connected. It is noted that the upper end of the inner filter screen cylinder 421 can also be directly supported on the casing 10.

In one embodiment, referring to FIGS. 2, 11 and 12 , the fan 20 includes a housing 21, a wind wheel 22 and a motor 23. The housing 21 is mounted in the casing 10, the wind wheel 22 is rotatably mounted in the housing 21, the position between the housing 21 and the wind wheel 22 forms an air duct. The wind wheel 22 is connected to the motor 23, and the motor 23 drives the wind wheel 22 to rotate in the housing 21. The motor 23 is supported in casing 10. Using wind wheel 22 can improve the aerodynamic performance of the fan 20 and reduce operating noise.

In one embodiment, the ratio of the inner diameter D1 of the air outlet end of the housing 21 to the outer diameter D2 of the wind wheel 22 is in the range of 1.2-1.6, that is, 1.2≤D1/D2≤1.6, that is, the inner diameter D1 of the air outlet end of the housing 21 is 1.2-1.6 times the outer diameter D2 of the wind wheel 22, which can not only ensure the good aerodynamic performance of the wind wheel 22, but also produces greater suction by the wind wheel 22 at the same speed, and can reduce the operating noise and keep the operating noise smaller, so that the operating noise of the air purifier 100 can be reduced, and the purification efficiency of the air purifier 100 can be improved.

In an embodiment, the ratio of the inner diameter D1 of the air outlet end of the housing 21 to the outer diameter D2 of the wind wheel 22 is in the range of 1.3-1.5, that is, the inner diameter D1 of the air outlet end of the housing 21 is 1.3-1.5 times the outer diameter D2 of the wind wheel 22, it can better ensure the good aerodynamic performance of the wind wheel 22, and the wind wheel 22 can produce greater suction, reduce the operating noise, and improve the purification efficiency of the air purifier 100.

In one embodiment, the inner diameter of the air inlet 210 is set as D, the outer diameter of the wind wheel 22 is set as D2, and D2-15 mm≤D≤D2-20 mm. This structure can ensure that more air enters the wind wheel 22 and improve the suction capacity of the fan 20.

In one embodiment, the area of the formaldehyde removal plate 422 is set as M, the inner diameter of the air inlet 210 of the fan 20 is set as D, and the outer diameter of the wind wheel 22 is set as D2, and:

${{1.3 \times {\pi\left( \frac{D}{2} \right)}^{2}} \leq M \leq {1.4 \times {\pi\left( \frac{D}{2} \right)}^{2}}};{{D2 - 15{mm}} \leqslant D \leqslant {2 - 20{{mm}.}}}$

This structure can reduce the wind resistance of the inner filter 42 and ensure that the area of the formaldehyde removal plate 422 is larger, so that more air enters the fan 20 through the inner filter 42 and improves the purification efficiency of the air purifier 100.

In one embodiment, referring to FIGS. 10 to 12 , the wind wheel 22 includes a plurality of moving blades 221, an air inlet guiding ring 223, and a baffle 222. The baffle 222 is connected to the motor 23, and the moving blades 221 are connected to the air inlet guiding ring 223 and the baffle 222. The moving blades 221 can be supported by the baffle 222. Arranging the air inlet guiding ring 223 to connect the air inlet guiding ring 223 to the moving blade 221 can increase the structural strength of the wind wheel 22 and better position and support the moving blades 221. The air inlet guiding ring 223 is rotatably supported in the housing 21, so that the wind wheel 22 can be positioned by the air inlet guiding ring 223 to ensure the wind wheel 22 rotates smoothly. During operation, the motor 23 drives the baffle 222 to rotate, drives the moving blades 221 and the air inlet guiding ring 223 to rotate, so that the air enters the moving blades 221 from the air inlet guiding ring 223 and flows out under pressure.

In one embodiment, referring to FIGS. 2, 11 and 12 , the baffle 222 includes a flat area 2221 and an inclined area 2222. The inclined area 2222 is arranged around the flat area 2221, and the peripheral side of the flat area 2221 is connected to the inclined area 2222. The flat area 2221 is located in the middle of the baffle 222, and the inclined area 2222 extends from the peripheral side of the flat area 2221 in a direction away from the air inlet guiding ring 223. With this structure, when the wind wheel 22 rotates, the inclined area 2222 of the baffle 222 can guide the airflow to the air outlet end of the fan 20 to reduce aerodynamic loss and improve aerodynamic performance. It is noted that the baffle 222 may also be provided with a curved surface structure with a middle part protruding toward the air inlet guiding ring 223. Of course, the baffle 222 can also be arranged in a flat structure to facilitate processing and manufacturing.

In one embodiment, the air inlet end of housing 21 is provided with a support plate 211, and the support plate 211 is extended inwardly from the air inlet end of housing 21, the support plate 211 is provided with an air inlet 210, and an end of the air inlet guiding ring 223 away from the baffle 222 is supported on the support plate 211, that is, the inner side end of the air inlet guiding ring 223 is supported on the support plate 211 to facilitate the support of the air inlet guiding ring 223, to ensure the smooth rotation of the wind wheel 22, and to reduce the gap between the housing 21 and the air inlet guiding ring 223, the gas backflow is reduced and the aerodynamic performance is improved.

In one embodiment, a convex ring 213 is provided on the support plate 211, and the convex ring 213 extends into the air inlet guiding ring 223, so that the air inlet guiding ring 223 can be positioned through the convex ring 213 to ensure that the wind wheel 22 is rotated more stable. In addition, this structure can also make the gap between the inner end of the air inlet guiding ring 223 and the convex ring 213 and the support plate 211 in a U-shaped, so that the U-shaped gap can increase the resistance of the gas backflow during the gas backflow, so as to improve the aerodynamic performance of the fan 20.

In one embodiment, referring to FIGS. 2, 10 and 8 , the inner filter screen cylinder 421 and the LED module 41 are supported on the air inlet 210 of the support plate 211, and the formaldehyde removal module 40 is supported on the air inlet 210 of the support plate 211, so as to purify the circulating air.

In one embodiment, a fixing plate 216 is provided on the support plate 211, and the LED module 41 is mounted on the fixing plate 216 so as to support the LED module 41.

In one embodiment, referring to FIGS. 2, 11 and 12 , the air inlet guiding ring 223 is bent from the outside to the inside in a direction away from the baffle 222, that is, the cross-section of the air inlet guiding ring 223 is arranged to be a C-shaped, and the inner side end of the air inlet guiding ring 223 is set to protrude away from the baffle 222, so that the air inlet guiding ring 223 can better guide the airflow, reduce wind resistance, and improve aerodynamic performance. It is noted that the air inlet guiding ring 223 may also be arranged in a flat ring shape. Of course, the air inlet guiding ring 223 may also be arranged in a flared shape inclined to the radial direction of the air inlet guiding ring 223, that is, the cross section of the air inlet guiding ring 223 is a plane inclined to the radial direction of the air inlet guiding ring 223.

In one embodiment, the housing 21 has a retracting pipe section 212, the retracting pipe section 212 is connected to the support plate 211, and the retracting pipe section 212 is arranged in a contraction direction toward the air inlet guiding ring 223. In this way, the gap between the retracting pipe section 212 and the air inlet guiding ring 223 can be made smaller, so as to increase the resistance of the gas backflow and improve the aerodynamic performance of the fan 20.

In one embodiment, the retracting pipe section 212 is provided with a first constriction portion 2121, and the first constriction portion 2121 is recessed toward the middle of the air inlet guiding ring 223, that is to say, the first constriction portion 2121 is the portion on the retracting pipe section 212 corresponding to the air inlet guiding ring 223, in this way, the gap between the first constriction portion 2121 and the air inlet guiding ring 223 can be made smaller, and the resistance of the gas backflow in the fan 20 can be increased to improve the aerodynamic performance of the fan 20.

In one embodiment, the retracting pipe section 212 is provided with a second constriction portion 2122, the second constriction portion 2122 is located at an end of the retracting pipe section 212 away from the support plate 211, and the second constriction portion 2122 is recessed toward, that is, the second constriction portion 2122 is recessed toward the center of the casing 10. The second constriction portion 2122 is located at the end of the air inlet guiding ring 223 away from the support plate 211, so that the gap between the end of the air inlet guiding ring 223 away from the support plate 211 and the second constriction portion 2122 is smaller, which increases the resistance of the gas backflow in the fan 20 to improve the aerodynamic performance of the fan 20.

In one embodiment, when the retracting pipe section 212 is provided with the first constriction portion 2121 and the second constriction portion 2122, the gap between the retracting pipe section 212 and the air inlet guiding ring 223 is bent in an S-shape, which can further increase resistance of the gas backflow in the fan 20 to improve the aerodynamic performance of the fan 20.

In one embodiment, the end of the air inlet guiding ring 223 away from the support plate 211 is provided with a convex edge 2231, and the convex edge 2231 is protruded from the air inlet guiding ring 223 toward the support plate 211, so that on the one hand, the convex edge 2231 is coordinated and positioned with the retracting pipe section 212 so that the wind wheel 22 rotates smoothly; on the other hand, the gap between the retracting pipe section 212 and the convex edge 2231 can be reduced, and the resistance of the gas backflow in the fan 20 can be increased to improve the aerodynamic performance of the fan 20.

In an embodiment, referring to FIG. 10 and FIG. 11 , a plurality of air guiding grids 214 and support strips 215 are provided in the air inlet 210, and the support strips 215 connect these air guiding grids 214 to support the air guiding grids 214. The support strips 215 are connected to the support plates 211, the air guiding grids 214 are in the shape of a flat sheet, and the thickness direction of the air guiding grids 214 are arranged along the radial direction of the wind wheel 22, so that the air entering the wind wheel 22 can be rectified to better guide the airflow into the wind wheel 22 to improve the aerodynamic performance of the fan 20.

In one embodiment, teach support strip 215 is in the shape of a sheet, and each support strip 215 is in the shape of a flat sheet. The thickness direction of the support strips 215 are arranged along the radial direction of the wind wheel 22, so that the support strips 215 can also rectify the air entering the wind wheel 22 to better guide the airflow into the wind wheel 22 and improve the aerodynamic performance of the fan 20.

In an embodiment, referring to FIG. 2 , FIG. 3 and FIG. 11 , the fan 20 also includes a diffuser 24, and the diffuser 24 is mounted on the housing 21. Arranging the diffuser 24 can reduce aerodynamic losses, improve the aerodynamic performance of the fan 20, and reduce the exhaust noise of the fan 20, and further reduce the operating noise of the fan 20.

In one embodiment, referring to FIGS. 2, 11 and 13 , the diffuser 24 includes an outer ring plate 242, an inner ring plate 241, and a plurality of stationary blades 243, and the plurality of stationary blades 243 are provided between the outer ring plate 242 and the inner ring plate 241 and the stationary blades 243 are connected with the outer ring plate 242 and the inner ring plate 241, so that a passage for airflow is formed between the outer ring plate 242 and the inner ring plate 241, so that the airflow discharged by the fan 20 can be guided and rectified, the airflow loss is reduced, the operating noise is reduced and the aerodynamic performance of the fan 20 is improved. The outer ring plate 242 is connected with the housing 21 to fix the diffuser 24 on the casing 10. The outer diameter of the inner ring plate 241 is smaller than or equal to the outer diameter of the wind wheel 22 to prevent the inner ring plate 241 from blocking the airflow out of the fan 20 and reduce the airflow resistance.

In one embodiment, referring to FIGS. 11 to 13 , the diffuser 24 further includes a mounting plate 25, the mounting plate 25 is connected to the inner ring plate 241, the motor 23 is mounted on the mounting plate 25, and the outputting shaft 231 of the motor 23 passes through the mounting plate 25 being connected to the baffle 222 to support the motor 23 through the mounting plate 25, so as to facilitate the mounting and fixing of the motor 23. Of course, a separate support can also be provided to support the motor 23 in the casing 10.

In one embodiment, the diffuser 24 further includes a cover plate 26. The cover plate 26 covers an end of the inner ring plate 241 away from the mounting plate 25, so that the cover plate 26, the inner ring plate 241, and the mounting plate 25 enclose to form the receiving cavity 201, and the motor 23 is placed in the receiving cavity 201, the outputting shaft 231 of the motor 23 extends out of the receiving cavity 201 and is connected to the baffle 222 to better mount and protect the motor 23.

In one embodiment, the mounting plate 25 includes a flat portion 251 and an inclined portion 252, the inclined portion 252 is arranged around the flat portion 251, the peripheral side of the flat portion 251 is connected to the inclined portion 252, and the flat portion 251 is located in the middle of the mounting plate 25 for supporting and mounting the motor 23. The inclined portion 252 extends from the peripheral side of the flat portion 251 toward the direction away from the wind wheel 22, and the edge of the inclined portion 252 is connected with the inner ring plate 241, so that the cover plate 26, the inner ring plate 241 and the mounting plate 25 can be increased the volume of the receiving cavity 201 formed therebetween, which can better receive the motor 23 and reduce the volume of the diffuser 24, thereby reducing the volume of the entire fan 20. Of course, the mounting plate 25 can also be provided in a flat plate structure to facilitate processing and manufacturing.

In one embodiment, the inclined portion 252 is provided with a plurality of through holes 253 to facilitate heat dissipation.

In one embodiment, referring to FIGS. 1 to 3 , the air outlet 110 is provided on the top of the casing 10, so that the casing 10 is arranged in a vertical structure to reduce the occupied space.

In one embodiment, the casing 10 includes an upper housing 11 and a lower housing 12, and the upper housing 11 is mounted on the lower housing 12. The upper housing 11 and the lower housing 12 are used to form the casing 10, which not only facilitates processing and manufacture, but also facilitates the mounting of various components in the casing 10.

In one embodiment, referring to FIGS. 1 to 3 , the air purifier 100 further includes a panel 51 mounted on the top of the casing 10, and the panel 51 is used to control the air purifier 100. Of course, in some embodiments, keys can also be provided on the casing 10 to control the air purifier 100.

In one embodiment, the air purifier 100 further includes a support shell 52, the support shell 52 is mounted on the top of the casing 10, and the panel 51 is mounted on the support shell 52, so that the panel 51 is supported on the top of the casing 10 through the support shell 52, and a gap is arranged between the panel 51 and the casing 10, so that the air can flow out between the casing 10 and the panel 51.

In one embodiment, referring to FIGS. 1, 2 and 9 , the top of the casing 10 is provided with a number of ribs 111 and a connecting ring 112. These ribs 111 are arranged around the middle of the casing 10, and the inner ends of the ribs 111 are connected to the connecting ring 112, that is, the end of each rib 111 close to the middle of the casing 10 is connected to the connecting ring 112 to ensure the good structural strength of the top of the casing 10. The air outlet 110 is formed between two adjacent ribs 111, and this structure can form a circle of air outlet 110 on the top of the casing 10, so that the purified air flow can spread around.

In one embodiment, the support shell 52 may be connected to the connecting ring 112 to support the panel 51 on the top of the casing 10. It is noted that the panel 51 can also be mounted on the connecting ring 112, and the panel 51 can be supported by the connecting ring 112.

In one embodiment, the support shell 52 is in a trumpet shape, and the diameter of the lower end of the support shell 52 is smaller than the diameter of the upper end of the support shell 52, so that when the purified air flows out from the air outlet 110, the support shell 52 can guide the air to the casing 10 diffusing on the peripheral side to increase the area covered by the purified air.

In one embodiment, referring to FIGS. 2 and 9 , the air purifier 100 further includes a wind guiding shell 53, and the wind guiding shell 53 is provided in the casing 10. One end of the wind guiding shell 53 is connected to the inner ring plate 241, and the other end of the wind guiding shell 53 is connected to the connecting ring 112. Arranging the wind guiding shell 53 can better support the connecting ring 112 and guide the airflow to the air outlet 110.

In one embodiment, the wind guiding shell 53 includes a circular section 531 and a contraction section 532. The circular section 531 extends along the axis of the wind wheel 22, one end of the circular section 531 is connected to the contraction section 532, and the other end of the circular section 531 is connected to the inner ring plate 241. The outer diameter of the connecting ring 112 is smaller than the inner diameter of the inner ring plate 241, and the contraction section 532 extends from the end of the circular section 531 away from the inner ring plate 241 toward the connecting ring 112, so that the space between the wind guiding shell 53 and the casing 10 is gradually increased from the circular section 531 to the air outlet 110, which can better diffuse pressure, and reduce airflow loss, the aerodynamic performance of the fan 20 is improved and the purification efficiency of the air purifier 100 is improved.

In an embodiment, the wind guiding shell 53 further includes a supporting plate 533, the edge of the supporting plate 533 is connected to the contraction section 532, and the supporting plate 533 is covered on the connecting ring 112, so as to better support the connecting ring 112 and ensure wind guiding shell 53 has good structural strength.

In one embodiment, referring to FIGS. 2, 11 and 12 , the air purifier 100 further includes a negative-ion generator 61 and negative-ion emission needles 62, and the negative-ion emission needles 62 are electrically connected to the negative-ion generator 61, the negative-ion generator 61 is mounted in the casing 10, and the negative ion emission needles are mounted at the air outlet 110. In this way, the air purifier 100 can generate negative ions for sterilization by the negative ions, thereby improving the efficiency and quality of air purification.

In one embodiment, the negative-ion generator 61 is mounted in the receiving cavity 201 to protect the negative-ion generator 61. The negative ion emission needles are mounted on the cover plate 26, so that the air flow discharged from the fan 20 passes through the negative ion emission needles, so that the discharged air flow contains negative ions.

The air purifier 100 in the embodiment of the present application has high air purification efficiency, low operating noise, long service life, which is convenient for replacing the filter 30, the coverage area of the purified air are wide, and structure is compact.

The above are only optional embodiments of the present application and are not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included within the protection of the present application. 

What is claimed is:
 1. An air purifier, comprising: a casing; a fan, mounted in the casing; and a filter, mounted in the casing, wherein the casing is provided with air inlet holes at a position adjacent to the filter, and at an end of the casing adjacent to an air outlet end of the fan is provided with an air outlet; wherein the filter is in a cylindrical shape, the air purifier further comprises a formaldehyde removal module, and the formaldehyde removal module includes an inner filter, the inner filter comprises an inner filter screen cylinder arranged in a cylindrical shape and a formaldehyde removal plate configured for removing formaldehyde in air, the formaldehyde removal plate is mounted at a bottom of the inner filter screen cylinder, and the formaldehyde removal plate is in a honeycomb shape, the inner filter screen cylinder is placed in the filter, and an upper end of the inner filter screen cylinder is fitted and connected with an upper end of the filter.
 2. The air purifier according to claim 1, wherein a total area of openings on the formaldehyde removal plate is set as S, an outer diameter of the formaldehyde removal plate is set as W, and a side length of the openings is set as a, and: $S = {\frac{3}{2}\sqrt{3}a^{2} \times {\left\lbrack {1 + {6 \times \left( {\frac{W}{\sqrt{3}a} - 1} \right)}} \right\rbrack.}}$
 3. The air purifier according to claim 1, wherein a distance between an outer surface of the inner filter screen cylinder and an inner surface of the filter is set as d, and 6 mm≤d≤9 mm.
 4. The air purifier according to claim 1, wherein a height of the filter is set as H1, and a distance from the formaldehyde removal plate to a bottom of the filter is set as H2, and H2≥⅓H1.
 5. The air purifier according to claim 1, wherein an area of the formaldehyde removal plate is set as M, and an inner diameter of an air inlet of the fan is set as D, and: ${1.3 \times {\pi\left( \frac{D}{2} \right)}^{2}} \leq M \leq {1.4 \times {{\pi\left( \frac{D}{2} \right)}^{2}.}}$
 6. The air purifier according to claim 1, wherein the fan comprises a housing, a wind wheel mounted in the housing, and a motor configured for driving the wind wheel to rotate, the housing is mounted in the casing, an inner diameter of an air outlet end of the housing is set as D1, and an outer diameter of the wind wheel is set as D2, and 1.2≤D1/D2≤1.6.
 7. The air purifier according to claim 6, wherein the wind wheel comprises a plurality of moving blades, an air inlet guiding ring and a baffle, the baffle is connected to the motor, and the moving blades are connected to the air inlet guiding ring and the baffle; the air inlet guiding ring is bent from an outer circumference of the wind wheel to a direction of a central axis of the wind wheel in a direction away from the baffle; an air inlet end of the housing is extended inwardly to provide with a support plate, the support plate is provided with an air inlet, and an end of the air inlet guiding ring away from the baffle is supported on the support plate.
 8. The air purifier according to claim 7, wherein an inner diameter of the air inlet is set as D, and D2-15 mm≤D≤D2-20 mm.
 9. The air purifier according to claim 1, wherein the inner filter screen cylinder is a photocatalytic filter screen, and the formaldehyde removal module further comprises a light source configured for illuminating the inner filter screen cylinder, and the light source is mounted in the casing.
 10. The air purifier according to claim 9, wherein the light source is an LED module placed above the inner filter screen cylinder.
 11. The air purifier according to claim 2, wherein the fan comprises a housing, a wind wheel mounted in the housing, and a motor configured for driving the wind wheel to rotate, the housing is mounted in the casing, an inner diameter of an air outlet end of the housing is set as D1, and an outer diameter of the wind wheel is set as D2, and 1.2≤D1/D2≤1.6.
 12. The air purifier according to claim 3, wherein the fan comprises a housing, a wind wheel mounted in the housing, and a motor configured for driving the wind wheel to rotate, the housing is mounted in the casing, an inner diameter of an air outlet end of the housing is set as D1, and an outer diameter of the wind wheel is set as D2, and 1.2≤D1/D2≤1.6.
 13. The air purifier according to claim 4, wherein the fan comprises a housing, a wind wheel mounted in the housing, and a motor configured for driving the wind wheel to rotate, the housing is mounted in the casing, an inner diameter of an air outlet end of the housing is set as D1, and an outer diameter of the wind wheel is set as D2, and 1.2≤D1/D2≤1.6.
 14. The air purifier according to claim 5, wherein the fan comprises a housing, a wind wheel mounted in the housing, and a motor configured for driving the wind wheel to rotate, the housing is mounted in the casing, an inner diameter of an air outlet end of the housing is set as D1, and an outer diameter of the wind wheel is set as D2, and 1.2≤D1/D2≤1.6.
 15. The air purifier according to claim 2, wherein the inner filter screen cylinder is a photocatalytic filter screen, and the formaldehyde removal module further comprises a light source configured for illuminating the inner filter screen cylinder, and the light source is mounted in the casing.
 16. The air purifier according to claim 3, wherein the inner filter screen cylinder is a photocatalytic filter screen, and the formaldehyde removal module further comprises a light source configured for illuminating the inner filter screen cylinder, and the light source is mounted in the casing.
 17. The air purifier according to claim 4, wherein the inner filter screen cylinder is a photocatalytic filter screen, and the formaldehyde removal module further comprises a light source configured for illuminating the inner filter screen cylinder, and the light source is mounted in the casing.
 18. The air purifier according to claim 5, wherein the inner filter screen cylinder is a photocatalytic filter screen, and the formaldehyde removal module further comprises a light source configured for illuminating the inner filter screen cylinder, and the light source is mounted in the casing. 